When aliphatic acids, such as fatty-acids, are suspended in aqueous solutions, stable foams can form on the surface. Stable foams can present a serious problem in many fields, such as industry, or chemical manufacturing. Stable foams can foul machinery and exist as residues and contamination on surfaces. Foams may be created in liquid handling when seals on pumps are leaky, low efficiency pumps leading to cavitation, bacterial growth, dirt contamination, systems are not designed properly, consistent pressure is not maintained within the system, and the like. Air can then enter into the system and become dissolved in the liquid, be entrained into the liquid causing bubbles to collect at the surface, and bubbles which rise to the surface and become foam. Such problems can lead to the need to perform costly repairs of instrumentation, cleaning of tanks and vessels or vats, cleaning of sieves and filters, and loss of production due to inconsistency of formulation. Such contaminating acids, present in foams or gels, can present significant cleaning problems since they are difficult to remove from surfaces and parts.
Aliphatic acids such as fatty acids, are carboxylic acids with a variable length, branched or unbranched aliphatic chain (tail). The tail may be saturated or unsaturated. Most naturally occurring fatty acids possess a chain of 4 to 30 carbon atoms. Fatty acids may be produced a number of ways, for instance by hydrolysis of the ester linkages in a fat or oil (triglycerides) with the removal of glycerol. Fatty acids can be troublesome side products of industry-scale chemical production methods, such as methods for producing detergents, pharmaceuticals, consumer products, coring and core analysis, oils, fuels, fermentation, emollients, moisturizers, liquors, foods such as seafood, milk, butter and other dairy products, water processing, paper products, and the like. Fatty acids may also be present in various consumer products, such as gels, soaps, or other fluids and can contaminate parts, machines, or other surfaces which come into contact with these products.
The “clean in place,” or CIP, industry has developed many methods for removing contaminants from machinery, vessels, equipment, and the like. Typically such methods call for several cycles of washing and rinsing wherein a cleaning solution is recycled through the system components to achieve solubilization and removal of the undesirable contaminants. (See, for instance, Bremer et al., Int'l. J. Food Microbio., 106:254-262, 2006).
Furthermore, there exist in the field many varied compositions which are directed to removing foam or preventing the generation of foam, commonly referred to as anti-foaming agents or defoamers. A defoamer is a chemical additive that reduces and hinders the formation of foam in industrial process liquids. Such chemical solutions are commonly employed in industrial settings to increase speed and reduce fouling of instruments and machinery. Such solutions are capable, in certain contexts, of reducing or eliminating surface foam and entrained, or entrapped, air in liquids. Defoamers can be generally categorized as oil-based, powder-based, water-based, silicone-based, glycol-based and alkyl polyacrylates. Defoamers are commonly used in the manufacturing of specialty detergents, carbonated beverages, fermentation, wood pulp and paper manufacturing, and in the pharmaceutical industry during capsulation.
Other caustic and hazardous cleaning solutions are known, such as provided, for instance, in U.S. Pat. Nos. 7,220,358, 7,569,532, 7,611,588, 6,737,394, 7,737,097 and 7,682,403, all of which are incorporated herein by reference in their entireties for all purposes. Though there are many varieties of cleaning solutions available on the market, there are no known solutions available which specifically solubilize aliphatic acids, such as fatty acids and derivatives thereof, especially cleaning solutions which are relatively non-toxic, non-caustic and not hazardous to handle, such that they may be useful in consumer products.
Among other aspects, the present invention provides methods and compositions that overcome the above noted limitations and permit rapid, simple, and effective removal and/or prevention of foams generated in solution by contaminating aliphatic acids, such as fatty acids. A complete understanding of the invention will be obtained upon review of the following.